Facebook has been under scrutiny on both sides of the Atlantic in the aftermath of the Cambridge Analytica data scandal.
The data firm connected to President Donald Trump's campaign, had access to information on about 87 million Facebook users without their knowledge.
This has opened doors to a broader question about privacy.
Mark Zuckerberg's visit to the European Parliament coincides with the introduction of the EU's new rules on data protection, which requires companies to give European citizens greater control over their personal data. But some believe that all publicity is good publicity.
James Hughes, a market analyst at Axitrader, says: "I think what this is for Facebook and Mark Zuckerberg is almost he's using it as a PR tour. I really think he's putting himself in front of different areas to say look we are open, we are transparent, yes we're not just a U.S. based company we're not just open and transparent in the area that we pay taxes in - we are open and transparent globally."
Facebook's data breach in the aftermath of the Cambridge Analytica data scandal has opened doors to a broader question about privacy.
After all when you sign up to the social media platform, you are joining a firm that makes money out of selling your data to advertisers.
Hughes says: "Privacy is key. We know that there's a continuous push we know the GDPR (General Data Protection Regulation) changes which have come in into law have affected most businesses. So there is a situation where Facebook are in line with privacy rules but it's a matter of showing that we're not going to get caught out again."
Many question remains such as whether there are other applications on the platform that collected similar or even more data.